Zinnia (Zinnia Elegans Dahlia Flowered Dream) - Would you like to grow these gorgeous annuals for your flower border? They are easy to grow from Zinnia seeds, and they make a brilliant cut flower with their blooms reaching an amazing 4 - 5 inches across! This dahlia flowered Zinnia in a rosy-lavender shade will bring lots of admiring comments! How to Grow Zinnias from Seed: In early spring, sow Zinnia seeds indoors using starter trays or small pots. Press the flower seeds into the soil and lightly cover with peat moss or sand. Keep soil slightly moist but not wet until germination occurs. Or after frost season has ended, directly sow Zinnia elegans seeds outdoors in a prepared seedbed with loosened, weed free soil. Sow the Zinnia seeds in rows 20 inches apart, spacing seeds every 6 inches. Thin to strongest Zinnia seedlings every 18 inches.